1. Field of the Invention
The present invention relates to a photoelectric conversion system.
2. Description of the Related Art
Among photoelectric conversion devices, such as an image sensor, that include an analog-to-digital converter (A/D converter), there has been proposed a type that further includes a diagnosis circuit for the A/D converter. According to Japanese Patent Application Laid-Open No. H11-331883, a checking signal is input instead of a pixel signal, a count signal is thus written at any time into a latch (column memory) provided for each column and then read the signal so as to perform diagnosis.